Hello Specialists..
I've designed a switching power supply using the TPS40200 controller. I made it using the SwitcherPro tool offered in TI Website.
If you try a design with the followings parameters,
TPS40200
V input min: 12V
V input max: 48V
V output: 5V
I output max: 3A
you will see a resistor (R10) of 10ohms between Vcc INPUT and the (C9) 4.7uF pump capacitor. Such resistor is a 0805 standard which does not disipate more than 0.10W. I think there is a mistake in the VccINPUT point of entrance. Shouldn't it enter from the 4.7uF end? That way, R10 will serve as Low Pass filter altogether with (C11) at the TPS40200 Vdd input (pin 8).
If I connect Vcc INPUT in the point specified in the SwitcherPro schematic, (R10) will not supply enough current to the 4.7uF and MOSFET.
Another question is: There is NO consistency between Schematic and Layout presented in the same SwitcherPro tool. You will find there is no resistor between Vcc INPUT and Rsense. Moreover, Rsense is (R6) in the schematic but this appears in the place of (R2), the FeedBack for the TPS40200.
I think there are some mistakes with SwitcherPro, let me know if I am wrong. And let me know too whether proceed with ensambling or not.
Tahnk You very MUCH.
Eng Ivan Perino
UNSL, Argentina